及物动词

1. 回报;报答
If your feelings or actions towards someone are reciprocated, the other person feels or behaves in the same way towards you as you have felt or behaved towards them.

1. alternate the direction of motion of

e.g. the engine reciprocates the propeller

2. act, feel, or give mutually or in return

e.g. We always invite the neighbors and they never reciprocate!